A review of the ladies' singles action on day five of Wimbledon 2014, including a win for Petra Kvitova and defeat for Li Na.

Venus Williams blinked first in a Centre Court battle of wits and booming serves as she lost a thriller to fellow former Wimbledon champion Petra Kvitova.

After a battle spanning two and a half hours, Kvitova broke the Williams serve for the first time in the match to earn a 5-7 7-6 (7/2) 7-5 victory.

It shattered hopes Williams had of reaching the second week of a tournament she has won five times.

"It's a shame there had to be a loser in this match and more of a shame that it had to be me," Williams said.

"But all I can say is that it's great to see women's tennis on such a high level. I always expect a great match when I play her. You look at our scorelines, they're never easy. She manages to somehow bring her best tennis against me.

"So when I walk out on the court, I have to expect that from her."

The 34-year-old American won the last of her seven slams in 2008 at Wimbledon but is determined not to give up the dream of an eighth.

She said: "I want to win grand slams. Everybody does. You don't get 'em. Look at what happened today. No-one gives it to you. They snatch it away and say, 'Mine'. That's what I'll have to do is snatch it, say, 'Mine', too, growl if need be.

At the age of 28, Strycova has enlisted a sports psychologist in a late-career effort to bring a new dimension to her game, and the Czech produced a stunning effort to see off the reigning Australian Open champion.

She clinched a 7-6 (7/5) 7-6 (7/5) win against China's leading sportswoman on Court One.

On match point, Li successfully challenged a call against her to gain a second life, but then immediately double-faulted.

The bizarre conclusion had Strycova initially puzzled.

"I didn't hear her challenge it," Strycova said. "I was so happy already that the match was over and suddenly she took the challenge and I had to get back to my concentration, but she did the double fault happily for me."

Caroline Wozniacki ended the run of 16-year-old Ana Konjuh to reach the fourth round at Wimbledon for the first time in three years, and she plays Strycova next.

Konjuh came through qualifying and won two rounds at a grand slam for the first time but found Wozniacki's experience and guile far too much as the Danish 16th seed triumphed 6-3 6-0.

Wozniacki said: "It feels great. I'm really pleased. My game is in great shape. I love playing at Wimbledon, so the more matches I can get the happier I am. It's exciting."

French Open runner-up Simona Halep presented a confusing account of her grass-court credentials as she mixed the brilliant with the distinctly average in a second-round Wimbledon win over Lesia Tsurenko, which had been carried over from Thursday.

Romanian Halep is the third seed after a stunning 13-month run on tour, in which she has won seven tournaments to sprint into the world's top five. And at times on Court Two against Ukrainian Tsurenko she lived up to her billing as the break-out star of the women's tour, but come the final point a 6-3 4-6 6-4 victory was a relief, with Halep punching the air in delight at getting the job done.

She said: "I believed in my chance, but after I lost the second set I said (to myself) that maybe I would lose the match because I didn't feel my game. It wasn't my best match, but I'm really happy that I could finish well in my way."

Halep is due to tackle Swiss 17-year-old Belinda Bencic in round three on Saturday, after last year's Wimbledon girls' champion beat American Victoria Duval 6-4 7-5.

They are catching up on the bottom half of the women's draw, in which third-round matches on Friday saw fourth seed Agnieszka Radwanska breeze through 6-2 6-0 against Portuguese qualifier Michelle Larcher de Brito, to be joined by Russian Ekaterina Makarova, China's Shuai Peng, and Czechs Lucie Safarova and Tereza Smitkova.